The invention relates to a concentrated one-coat mortar, and more specifically to a concentrated one-coat mortar suitable to add with cement and with light sand or its equivalent and finally to be mixed with water in proportions that provide for an even application (smooth or textured). The invention further relates to a concentrated one-coat mortar that avoids cracking through a wide range of temperatures and humidities while forming a monolithic surface.
Concrete-based materials are widely used on buildings or other structures to provide an even exterior surface. The concrete-based materials are spread over a rough concrete surface. Such rough concrete surfaces typically include bricks, blocks or stones that are held together by a cement (or concrete).
The application of a coat of mortar involves first preparing the mortar. The mortar is mixed with sand and water to the desired consistency. It is then applied to the rough concrete surface using a smooth trowel. This creates an even exterior finish that is both attractive and resistant to weather.
Concrete-based materials for providing an even exterior surface are widely known, and commonly used in the construction arts. For example, U.S. Pat. No. 4,222,785, issued Sep. 16, 1980, to Henderson, teaches a concrete-based material suitable for application to the exterior of a building. This particular mixture provides certain insulating characteristics.
U.S. Pat. No. 4,229,225, issued Oct. 21, 1980, to Kraszewski et al., teaches another concrete-based material suitable for application to the exterior of a building. This particular mixture includes:
20-60% cement;
30-70% inorganic or organic filler;
2-10% zirconium, hafnium, vanadium or cesium silicate fibers;
0.2-1% plasticizers for cement;
1-3% adhesive; and
0.1-0.5% water-repellent.
This above mixture provides certain water-repellent characteristics discussed therein.
U.S. Pat. No. 4,741,777, issued May 3, 1988, to Williams et al., teaches another concrete-based material suitable for a coat application to the exterior of a building. This particular mixture includes:
23% Portland cement;
68.55% sand;
6% Fly ash type F;
1% glass fiber,
1.25% vinyl acetate-ethylene co-polymer powder form;
0.15% sodium salts; and
0.05% defoamer or antifoam agent.
Still other related cement mixtures are taught by:
U.S. Pat. No. 5,690,729, issued Nov. 25, 1997, to Jones, Jr.;
U.S. Pat. No. 5,651,816, issued Jul. 29, 1997, to Kobayashi et al.;
U.S. Pat. No. 5,460,648, issued Oct. 24, 1995, to Walloch et al.;
U.S. Pat. No. 5,378,279, issued Jan. 3, 1995, to Conroy;
U.S. Pat. No. 4,746,552, issued May 24, 1988, to Tokumoto et al.;
U.S. Pat. No. 5,728,209, issued Mar. 17, 1998, to Bury et al.; and
U.S. Pat. No. 5,965,201, issued Oct. 12, 1999. Each of the above-identified patents are expressly incorporated herein by reference.
Despite the selection of additives and range of combinations heretofore available, the search for a combination of constituents that provides the xe2x80x9coptimumxe2x80x9d mixture continues. In many cases, the addition of a constituent to enhance one characteristic (e.g., workability) adversely affects or effects another characteristic (e.g., slump).
In the application of a coat mortar, the mortar""s properties are especially critical. The mortar must form a strong bond with the underlying rough surface and at the same time provide an even exterior surface.
In addition, application conditions significantly affect a mortar""s properties. Increased temperatures tend to accelerate the drying process and, in many mixtures, cause small cracks to form in the forging mortar. These are obviously undesirable, but very difficult to avoid with commercially available mixtures.
It is an object of the invention to provide a concentrated mix to cover surfaces identified herein as concentrated one-coat mortar. The concentrated one-coat mortar is suitable for application in wide range of climactic conditions. It especially avoids the formation of cracks in the finished surface.
In one preferred embodiment of the invention, the concentrated one-coat mortar is provided for mixing with cement, sand and water; in another preferred embodiment of the invention, the concentrated one-coat mortar includes cement and is provided for mixing with sand and water; in another preferred embodiment of the invention, the concentrated one-coat mortar includes sand and is provided for mixing with cement and water.
It is a further object of the invention that the concentrated one-coat mortar should provide properties that include strong bonding to the underlying surface, impermeability to water but permeability to water vapor, acoustic and thermal insulation, and elasticity.
According to one preferred aspect of the invention, a concentrated one-coat mortar is especially suited to mix with sand and cement as may be available at the job site, and prevents cracking when applied in relatively high and low temperature conditions. The mortar is composed by weight of approximately 40% cement, 54% calcium carbonate (preferably controlled graining between 0.63-0.66 mm in the fine/thin part of the granularity; for then it would use from 20-25% of calcium carbonate; and 1.8-2 mm in the thick part of the granularity; for then it would use from 75-80% of calcium carbonate), 2.5% light sand, 0.6% hydrofuge agent, 1.8% cellulose fiber, 0.4% cellulose ether, and 0.5% dispersible pulverized resin.
According to further aspects of the invention, the preferred range of the composition varies within a range of +/xe2x88x923% for the cement, +/xe2x88x924% for the calcium carbonate, +/xe2x88x920.2% for the sand, +/xe2x88x920.04% for the hydrofuge agent, +/xe2x88x920.04% for the cellulose fiber, +/xe2x88x920.02% for the cellulose ether, and +/xe2x88x920.02% for the dispersible pulverized resin.
According to still further aspects of the invention, the preferred range of the composition varies within a range of +/xe2x88x9212% for the Portland cement, +/xe2x88x9216% for the calcium carbonate, +5%/xe2x88x921% for the sand, +1%/xe2x88x920.6% for the hydrofuge agent, +3%/xe2x88x920.8% for the cellulose fiber, +3%/xe2x88x920.04% for the cellulose ether, and +1%/xe2x88x920.5% for the dispersible pulverized resin.
According to a further aspect of the invention, the concentrated one-coat mortar does not include sand so that it is mixed in 1:1 proportion with sand (such as beach sand or silica) or pulverized aggregate (such as calcium carbonate) and water on site. Also, this concentration can be without cement so that the cement is added on site in to the desired consistency. In either case, the mix is prepared on-site in accordance with prevailing conditions.
According to a further aspect of the invention, the improved concentrated one-coat mortar uses sodium oleate for the hydrofuge agent. This provides the impermeability to water and permeability to water vapor.
According to another aspect of the invention, the improved concentrated one-coat mortar is applied to a rough concrete surface to form an even or textured exterior surface.